In a photolithography process in manufacturing, for example, a semiconductor device, for example, a plurality of kinds of heat processing such as heat processing of evaporating a solvent in a resist film applied on a wafer (pre-baking), heat processing of accelerating the chemical reaction in the resist film after exposure of a pattern post-exposure baking), and heat processing after developing treatment (post-baking) and so on are performed
The above heat processing is usually performed in a heat processing unit by mounting and heating the wafer on a heating plate. To manufacture semiconductor devices uniform within the wafer, it is necessary to heat the wafer at a temperature uniform within the wafer. To this end, a heating plate is used which is divided into a plurality of regions and temperature-settable for each of the regions.
Incidentally, the temperature setting of the heating plate performed before the heat processing is performed using a temperature measuring wafer which is mounted on the heating plate to measure the temperature (see Patent Document 1). Usually, the temperature measuring wafer is mounted on the heating plate and kept standing until the measurement temperature by the temperature measuring wafer becomes uniform within the wafer, and at a point in time when the temperature becomes uniform, the temperatures of the regions of the heating plate are set. Usually, it takes about 10 minutes to about 20 minutes until the temperature within the wafer becomes uniform after the temperature measuring wafer is mounted on the heating plate.
However, when the temperature setting of the heating plate was performed at the point in time when the in-plane temperature of the temperature measuring wafer became uniform after the temperature measuring wafer was mounted on the heating plate and kept standing for about 10 minutes to about 20 minutes as described above, actually it was verified that the temperature within a wafer to be processed did not become precisely uniform in an actual wafer processing period which is finished in about 60 seconds to about 90 seconds after the wafer is mounted on the heating plate. This can cause, for example, variations in patterns formed on the wafer by a photolithography process.
[Patent Document 1]
Japanese Patent Application Laid-open No. 2002-124457